Method of and apparatus for applying coating



H. W. DAY. METHOD OF AND APPARATUS FOR APPLYING COATING.

' APPLICATION FILED MAR.1 1920.

1,368,612. Patented Feb. 15, 1921.

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' UNITED STATES PATENT OFFICE.

HERBERT w. DAY, or woLtAsToN, MASSACHUSETTS, ASSIGNOR To SPRAY ENGllI- NEERING COMPANY, or BOSTON, MASSAcHUSETTS, A CORPORATION or MASSA- GHUSETTS.

METHOD OF AND APPARATUS FOR APPLYING coATINe.

Specification of Letters Patent.

. Patented Feb. 15, 1921.

Application filed March 12, 1920. Serial No. 365,347.

To all whom it may 00mm.-

This invention relates to method of and apparatus for applying coating'to surfaces,

. ing, wherein I have represented a single and in its preferred embodiment is an improvement upon the construction disclosed in my Patent No. 1,321,014, dated November 4, 1919.

The coating, if a liquid, may be a paint, japan, varnish or any other suitable coatmg medium, or itmay, if desired, be a Solid in powdered form, and the material or surface to which it is to be applied may be of any character, such, for example, as

' wood, metal or other material.

Referring more particularly to the drawembodiment of my invention,-

Figure 1 is a vertical longitudinal section of a tool constructed in accordance with my invention Fig. 2 is an end elevation of the tool, looking toward the right in Fig. 1; and i Fig. 3 is a verticalsection upon the line 33 of Fig. 1, looking toward the right in said figure.

The tool or appliance may be of any suit able material but is preferably metallic and may be of the general form shown in my Patent No. 1,172,233, dated February 15, 1916, or of anyother suitable form or construction. The body 1 is, however, preferably provided with a handle or extension 2 integral therewith and provided with a guard 3 inclosing the free end of the valve operating lever 4 pivoted at 5 upon the body 1. In the disclosed form of the invention, the said operatinglever 4 is of general trigger form, but such construction may be widely varied within the scope and purpose ofv the invention.

The handle 2 is provided with a passage 6 for the paint or other suitable coating liquid or powder, which may be supplied if desired and also with a passage 7 for the air or other suitable fluid under pressure. In the form of tool herein Shown, I have represented the passages 6, 7 as pipes suitably secured in the body 1 andz'as communicating at their inner ends with passages 3, 9 cored or otherwise suitably provlded m the body 1. Controlling the paint supplypassage 8 is a valve which may be of any sultable form, but which is herein represented as an axially movable piston or plunger 10 positioned within a valve casing 11 and having a stem 12 extending through the valve easing into contact with the operating lever 4, as clearly shown in Fig. 1. The yalve here shown as a piston or plunger is normally held seated by a coiled spr ng 13 surrounding the stem '12 and Seated in a recess 14 in a cap 15 threaded at 16 into the body 1 similarly threaded at 17.

The passage 9 for the air is controlled by a snnllar valve indicated generally at 18 in Fig. 2, the spindle 19 thereof contacting with the valve operating lever 4 which is shaped so as to engage bothvalves "in a illustrate.

The body 1 is cored to rovide a longitudinal passage 20 whic is internally threaded at 21, 22 for the reception respectively of a tubular member "23 threaded at 24.and a needle valve 25 threaded at 26-. The tubular member 23 at its forward end is preferably suitably formed to permit the passage of the coating material issuing from the valve chamber 10 into the passage 27 and thence into the circumferential space 28. For this purpose, the forward end of the tubular member 20 is preferably squared. Thus the coating material, when the valve 10 is opened, is permitted to flow through the passage 6, the valve casing 11, the passages 27, 28, and thence past the squared.

formation. Upon the forward end of the tubular member'20 is threaded or otherwise positioned a cap 30, which may if desired be similar to the corresponding member in my PatentNo. 1,172,233. The needle valve 25 is seated at its outer end in the cap 30 as indicated in Fig. 1, and the forward end of the said needle valve is guided and positioned by any suitable means, as, for example, by a coiled wire 31 encircling the head of the valve and maintaining it in a central position when the valve is unseated. The rear end of the valve 25 may be provided with a'suitable lock nut 32.

The air passage 9 is in communication with a passage 33 indicated in dotted lines in Fig. 1, which is itself in communication through the passage 33 past the valve 18- through the passages 34, 35 and into the passage 36 governed or controlled by the through the film at the centralportion of needle valve 25.

Upon the outer end of the body 1 is threaded or otherwise suitably secured a preferably cap-like member 37 herein shown as having a concaved or curved inner surface 38 and a small central opening 39 in line with the axis of the needle valve 25. Thelength of the threaded portion 40 of the cap like member 37 is sufl'icient to permit adjustment of the member 37 so as to provide for the effective formation of a film and the variation of the thickness thereof as described in my Patent No. 1,172,233. Such film is constantly formed and maintained by capillary action vbetween ,the surface 38 and the outer surface 41 of the inner cap 30 which are broughtclose enough together to insure such action. The air entering through the passage 36 breaks the cap and discharges the .same upon the work in very fine globules. Said film is constantly broken by the, air or other fluid but is constantly restored through the action of capillarity. Hence the coating ma-.

terial may be merely under suction due to capillary action. The maintenance of the supply of coating material is not dependent upon the presence of the air, current which is used merely to break the film and.

discharge the globules. I effect through the described construction a'veryfine division of the 'coatin material as set forth in my said Patent' 0. 1,172,233. The construction of parts thus far described effects the formation of a mass of spray of general through the orifice 39, but. generally ciring by means of supplemental jets of aircular in cross section.

This result is effected by. the disruption 'of the film formed between the cap like members 30, 37 through the agency of the air or othensuitable fluid in the manner already described. i p

I am awarethat it has been proposed to modify the character of the spray issuing from a tool or appliance for applying coatdirected upon .the discharged spray, as

conical Y form issuing shown, for example, in the patent to Burdick, No. 649,430, dated May. 15, 1900, and. also in the patent toDe .Vilbiss & Mueller,

No. 1,260,522,'dated March 26, 1918. In

or transform the issuing spray from a conical formation. circular in cross section into a sheet. In sald patent, I dlsclosedmeans and a process whereby a mass of spray as discharged may be given'any form in cross section between that of a relatively thin sheet and a cone or mass circular in cross section. I effect this same general result in accordance w1th my present lnventlon.

' To that end I provide as broadly disclosed in my said Patent No. 1,321,014, a generally cylindrical member 42 having any suitable number and herein two tubular extensions 43, 44, preferably diametrically opposed to each other and terminating in the discharge passagesv 45, 46 inclined toward each other and clearly. represented in T'he twm or other number ofsupplemental air passages 43, 44 are desirably in constant communication at their inner "ends through passages or ports 47, 48 with a completely annular passage or groove 49 shown as formed upon the outer surface of the forward end of the body 1, and indicated also in Fig. 3.

As disclosed in my Patent No. 1,321,014, A

' the member provided for thedischarge of supplemental air jets was provided'with a substantially spherical inner surface adapted to be received upon a correspondingly shaped portion of thebody of the tool.

The construction disclosed in this application constitutes an improvement upon that of my said patent in that I guard against all possibility of leakage of the air and even of the coating material due to wear, and I also provide for adjustment of the member 42 longitudinally of the tbol, that is, in a direction that will move the terminals of the discharge passages 43, 44 forwardly or rearwardly with respect to' the point at which the main compressed air supply and the coating. are discharged; from the tool. I s

material by advancing the point at which the supplemental air impacts upon'the discharged mass of coating material; that is to say, by advancing said point forward with respect to the point of discharge of the coating material from the tool, I discharge the supplemental air jet or jets upon the discharged coating material at a point where the main discharged air supply has slightly spent its force and where the supplemental i air jets are thus permitted with a given pressure to break up and transform the shape of the discharged mass of coating material more effectively. Thus by advancing the point or points of supplemental air discharge, I may discharge the air supplementally under less pressure and secure the same breaking up effect that would be secured with a greater pressure and with the points of supplemental air discharge at a more rearward position. Therefore, I am enabled in the practice of my invention and in accordance with my process to vary the breaking up effect produced by the supplemental air discharge byvarying the point at which such supplemental 'air discharge impinges upon the discharged coating material, such point being varied, in a to and fro or longitudinal direction with respect to the longitudinal axis of the tool.

Preferably I accomplish this result by providing the surface. of the body 1 with a thread 50 which is preferably both in advance of and in the rear of the annular passage or groove 49. I also provide a thread, as indicated at 51 upon the inner surface of the cylindrical member 42 both in advance of and ,in the rear of the openings or ports 47, 48 therein.

The annular passage or groove 49 is of such diameter that a substantial longitudi-' nal adjustment is permitted of the member 42-without destroying the air communication between the ports 47, 48 and the annular passage or groove 49. Desirably I make the annular groove or passage 49 of considerable width for this purpose, and the ports 47, 48 maybe and desirably are some- 1 what elongated in the direction of the longitudinal axis of the member 42. The threads 50, 51 provide for a very close union between the member 42 and the body 1 and yet of a character permitting the very ready adjustment of the member 42.

' The annular passage or groove 49, and hence the passages 43, 44 are in communication with the longitudinally extending passage or groove 49 may if desired be formed in the inner surface of the member 42 and that the openings 47, 48 may be provided in the body 1. It will be understood from the foregoing description that the supple mental air passages 43, 44 are in constant communication with the annular passage or groove 49 whatever he the circumferential position of the cylindrical member 42, that is, provided the member 42 has not been adjusted far enough longitudinally in a forward direction with respect to the point of discharge of the coatingsmaterial to cut oil" such communication. esirably I do not interrupt or cut off the discharge of the supplemental air jets by movement of the cylindrical member 42 longitudinally of the body 1, but do this wholly through manipulation of the valve 55. The purpose of the longitudinal adjustment of the member 42 is to vary the point at which the supplemental air jet or jets is or are permitted to impact upon the discharged coating material with the results and advantages hereinbefore set forth.

My invention in its broadest application is. not limited to the formation of a film of the coating material, since such coating material may be positioned with respect to the dischargin manner. referably, however, I provide for forming, breaking through and discharging the film.

It will be observed that the member 42 is capable notv only of lon itudinal adjustment for the purpose set fort but is mounted for circumferential or rotary movement upon the body 1, so as to secure any desired plane of the sheet of coating material and to main tain such plane thereof. Both the longitudinal and the rotary or circumferential adjustments are secured without the necessity of interrupting the communication between the supplemental motive agent discharge passages of the member 42 and the motive agent supply passage of thememher 1.

Having thus described one illustrative embodiment of my-invention andv the method of practising the same, I desi e it to be understood that although specific terms are employed, they are used in a generic and demotive fluid in any suitable ,10 mass or cloud and varying the point or I forth in the scriptiv'e sense and not for purposes of limicharging it as a mass or cloud, supplement charging ally discharging compressed air upon said points of impact of the supplementally dis-' charged compressed air upon said mass or cloud with respect to the point of emergence of said mass or cloud. v 2. That method of applying coatin comprising supplying coating materia discompressed motive fluid against material, thereby effecting the ereof as amass or cloud, dissaid coatin discharge t charging motive ,material supplementally upon said mass or cloud and varying with res 'ect to the point of dischargefof the mass .or cloud the point or points of impactof the supplementally discharged motive fluid,

thereby varying the breaking up effect of the said-supplemental discharge of. motive -3..That method of applfying coating comprising providing a film o disch film thereby disrupting the same and discoating material,

charging it as a mass or cloud, discharging a plurality of streams of compressed air upon said massor cloud, and varying in a forward or backward direction with respect to the point of discharge of the mass or cloud the points of impact of the supplemental streams of compressed air, thereby varying the breaking up effect of suchsupplemental streams of air at a given pressure. r

4. Means for applying coating comprising means for maintalning a film of coating material, means for causing a motive agent to and d1scharge\ said film,

break through means to discharge the motive agent supplementally upon the discharged film to transform the latterinto a mass having a difi'erent crosssecti'on, and means to advance or retract with. respect tothe point of discharge of the film, the point of impact of the supplemental motive agent. upon the dischar ed :tive agent supplemental charged coating materia change lengthwlseof the discharged coat film, thereby to vary the breaking up e ect of the supplemental motive agent.

5. Means for applying coating comprising means to supply coating material; means to subject the same to the'actionof a-motive agent, thereby efiecting the discharge ofthe coating material, means to discharge a mo- .upon the die and means tov ing material, the point of impact (2f the supar 1n com ressed air -a ainst said threaded surfaces material and stantia'lly cylindrical member 42 supported supplemental air to permit .sage of the body,

being adjustable upon the tool longitudinally of the axis of the latter, thereby to upon the said disc5 vary the point of impact of the supplemental motive agent upon the discharge coating material.

7. A tool for applying coating comprising a bod having passa es for coating material and or a motive Euid under pressure, a member supported upon saidbody and having one or. more supplemental motive agent discharge passages in uninterrupted and continuous communication with the motive agent supply passage, and means for effecting longltudinal adjustment of said member.

8. A tool for applying coating comprising a body having and for a motive agent under ressure, and a member supported upon sa1d body and having one or more supplemental motive agent discharge passages in, communication with the motive agent supply passage, said member'being adjustable upon the tool in a direction longitudinally of the axis-"ofsaid tool for the urpose set forth.

9. A tool or applying coating comprising passages, for coating material and for a motive agent under pressure, and a membersupported upon said body and having .one or more supplemental motive agent discharge passages in communication with the'motive agent supply passage, said tool body and member having interengaging permitting longitudinal adjustment of said member. I

10. Means for applying coating comprising a. body having passages for the coating for air under pressure, a suband having a plurality of passages 43, 44, said body and member having communicating passages47, 48, 49, said body and member having interen'gaging threaded surfaces 50,51 longitudinal adjustment of said member 42.

upon sa1d body- 11 .iMeans for applying coating compris-' I 1 g a body having passagesfor coating material and *for a motive fluid under ressure cation with the 'motive\agent supply pascapable of longitudinal adjustment with resaid' member 42 beingspect to saidbody without interrupting themember and the motive agent supply pas- .o

sage in the body.

12. A tool for applying coating comprising a body having passages for coating material and for a motive agent under pressure and a member supported upon said body and having one or more supplemental motive agent discharge passages in com- 10 munioation wlth the motive agent supply passage,- said member being mounted for circumferential movement and for longi tudinal adjustment upon said body.

In testimony whereof I have signed my 15 name to this specification.

HERBERT W. DAY. 

